Test 1 Strcture and Function

Test 1 Strcture and Function - January21 2011 1665 Robert...

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January21, 2011 1665 Robert Hooke was the first to describe microorganisms. He created a magnifying glass and could see microorganisms. 1676 Antoni Van Leeuvenhoiek was the first to describe bacteria. 4 Types of Light Microscopy 1. Brightfield Most Common o Simplest o Specimen illuminated, magnified 1000x o Specimen stained to increase contrast. 2. Phase Contrast & 3. Darkfield o Visualize live samples o No staining required o Image contrast derived from cell structure Brightfiled Phase Contrast Darkfield 4. Fluorescent o Visualization of auto-fluorescent molecules or fluorescent stains. Chlorophyll autofluorescence Chlorophyll autofluorescence
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Compound Light Microscopes - Brightfield, phase-contrast, darkfield, fluorescent. - Optimize image resolution by using lenses with high light-gathering characteristics - Limit of resolution ~ 0.2 μ m Electron microscope - Limit of resolution ~ 0.2 - 0.4 μ m - Two types of electron microscopy 1. Transmission Electron microscope (TEM) for internal structure. 2. Scanning electron microscope (SEM) for three-dimensional imaging and viewing surfaces
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Mycobacterium Hanson’s Disease (Leprosy) carried by armadillos. Significance of Being Small Microorganisms are as small as .2 Size affects physiology, growth rate, and ecology. 0.2microns is the size of the smallest free-living pathogenic bacterium Mycoplasma pneumoniae . 750microns is the largest prokaryote Thiomargarita namibiensis a spherical sulfur chemolithotroph. High surface area-to-volume ratios aid in the nutrient and waste exchange with the environment. January 24,2011 Basic components of all microbial cells - Cytoplasm - Cytoplasmic membrane - Ribosomes Two structural types of cells are recognized - Prokaryotes ( Bacteria and Archaea) Nucleoid- the space in the cell where DNA is found. .. it’s a Location Both Plants and Bacterial cells have cell walls.
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- Eukaryotes (Eukarya) Golgi (Post Office) - where things go. Mitochondria aren’t found in all cells. Eukaryotic cells > Prokaryotic > Virus Yet there ranges overlap in size. Cytoplasmic Membrane Fluid highly selective permeability barrier. Made of lipids and proteins Phospholipids form a lipid bilayer with polar exteriors and non polar interior Ester linkage of fatty acids to glycerol.
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Other lipids in Cytoplasmic Membrane Sterols in Eukarya (Cholesterol) Hapanolds in Bacteria (Diploptene) Achaea Lipid Monolayer More resistant to peeling apart than bilayer There is no break [Biphytanyl] -ether linkage (double bonded Oxygen) is missing Functions of Cytoplasmic Membrane 1. Permeability prevents leakage and functions as a gateway for transport of nutrients into and out of the cell. 2. Protein Anchor
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This note was uploaded on 06/13/2011 for the course BIOL 2051 taught by Professor Brininstool during the Spring '07 term at LSU.

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Test 1 Strcture and Function - January21 2011 1665 Robert...

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